bit of a pickle, php xml parser

[morleymouse]

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im not too up on the whole xml / php parser type stuff but cobbled this together to parse some XML fro ma variable ($xml)

<?
$xml = "all my xml data here - it comes from a database";

$parser = xml_parser_create(  ); 
xml_parser_set_option($parser, XML_OPTION_CASE_FOLDING, 0);
xml_parse_into_struct($parser,$xml,$values,$index); 
xml_parser_free($parser);
        
for($i = 0; $i <= 200; $i++) { 
        
    $desc = $values[$index[desc][$i]][value];
    $title = $values[$index[title][$i]][value];
    $url = $values[$index[infourl][$i]][value];
//    $type = $values[$index[type][$i]][value];

if ($title): ?>

I can then print out my content here
<? echo $desc; ?> etc etc from above.

<?
endif;
}
?>

Quick explanation behind it, the whole $i up to 200 thing, its because I know there wont ever be more than 200 items, the if($title) makes sure I dont echo blank entries onto the page.

I dont actually know what:

$parser = xml_parser_create(  ); 
xml_parser_set_option($parser, XML_OPTION_CASE_FOLDING, 0);
xml_parse_into_struct($parser,$xml,$values,$index); 
xml_parser_free($parser); 

does so if anyone fancied explaining that it'd be nice!


the problem...
the $type (commented out i nthe above script) messes it all up. Some of the xml entries have a <type>something</type> but others dont have any <type> tags at all. So when the script runs through it it seems to move the types up. So if the 12th item has a type of say "green" it moves it up and the first item shows as having a type "green" and if no other tpyes are i nthe xml then item 12 whic hshould be green has no type with it.

kind of complicated, I know how to fix it but dont know how to FIX it.

I need the script to check each section of data for the tag and if it doesnt exist leave it blank or something like that?

sample xml data for this...

<xmldata>
<data>
<desc></desc>
<url></url>
<type></type>   (not always there)
</data>
<data>
<desc></desc>
<url></url>
                         (see gone)
</data>
</xmldata>

sorry if ive made this a bit lengthy but would be ever so greatful if anyone could help!

[drivetowin]

Don't know if this will work but have you tried

if ($values[$index[type][$i]][value]){
$type = $values[$index[type][$i]][value];
}

[morleymouse]

ill give it a shot cheers, but I have a sneeky suspicion that it wont...

what I thin kthe script is doing is just going throug hall the data until it finds the type tag and using it, doesnt matter which <data></data> it comes from, so...

if ($values[$index[type][$i]][value]) 

would be true, as it finds a type tag somewhere i nthe data and then it would use that again

might be wrong like I said ill try it but thats my sneeking suspicion


edit: cant check it now, changed some stuff earlier and dont have access from home to get them back. grrr ill be back tomorrow no doubt!

[dmorison]

Hi Dan,

When I first started using PHP's XML functions a few years ago I had a look at parse_into_struct and my head nearly blew up!

I tend to use the event handler method of parsing; as you have complete control over the data structure that you are creating. Here's something that should do what you want - a quick tested knock up! (hooray for "php -a" !!)

<?php

// this is your sample XML with some fields missing in each record

$xml = "
<xmldata>
  <data><desc>Foo</desc><url>someurl</url><type>TEST</type></data>
  <data><desc>Bar</desc><url>someotherurl</url></data>
</xmldata>
";

// start an array to parse the records into

$records = array();

// create a function to handle the opening tags in the XML
function xmlStartTag($parser, $name, $attribs)
{
  global $currentRecord;  
  global $currentTag;
  global $inRecord;  
  if ($name == "DATA") // each of your records starts with <data> so start a new $currentRecord
  {
    $inRecord = true;      
    $currentRecord = array();
  }  
  if ($inRecord)
  {
    $currentTag = $name;
  }
}
// create a function to handle the data between tags
function xmlCDATA($parser, $cdata)
{
  global $currentRecord;  
  global $currentTag;    
  $currentRecord[$currentTag] .= $cdata;
}
// create a function to handle the closing tags in the XML
function xmlEndTag($parser, $name)
{
  global $records;
  global $currentRecord;
  global $inRecord;  
  if ($name == "DATA") // ditto, this means we've reached the end, so add the current record to the $record array :)
  {
    $inRecord = false;
    $records[] = $currentRecord;
  }
}

// create an XML parser resource
$parser = xml_parser_create(); 
// register the functions to handle the beginning and end of each tag
xml_set_element_handler($parser, "xmlStartTag", "xmlEndTag");
// register a function to handle the data between tags (cdata)
xml_set_character_data_handler($parser, "xmlCDATA");
// parse your string, the true value means there's no more data to come
xml_parse($parser,$xml,true); 
// free it up
xml_parser_free($parser);

// now you've parsed the records into $records have a look using print_r()
print_r($records);

?>

You could then go on to traverse the $records array using foreach, and the print out each of the expected parameters after testing to see if they are set, just as you are doing now:

foreach($records as $data)
{
  print $data["DESC"]."<br>";
  print $data["URL"]."<br>";
  if ($data["TYPE"]) print $data["TYPE"]."<br>";
} 

Hope this helps! (i've lived and breathed XML for the past 2 years as you know! )

[morleymouse]

thank you loads!

[km8]

Don't know if this will work but have you tried

if ($values[$index[type][$i]][value]){
$type = $values[$index[type][$i]][value];
}

I think the problem is that $type is set from the previous run through the loop.

Try this - should set $type to nothing if it doesn't exist for this item.

if ($values[$index[type][$i]][value]){
$type = $values[$index[type][$i]][value];
}
else {
$type="";
}